1. Field of the Invention
The present invention relates to goggles. More particularly, the present invention relates to goggles having a dual lens structure for use in recreational activities.
2. Description of Related Art
Eye protection adapted for recreational activities are well known and widely used to protect the eye from impact damage or visual disturbances caused by air or water flow directed toward the eye. In contrast to eyepieces that are used to correct vision defects, recreational goggles are routinely used in applications that require protection of the eye.
Conventionally, eye wear for recreational use is held in place adjacent the eye by a combined headband that extends about the rear of the head, a nosepiece that extends across the nose, and in the case of swim goggles, suction cups that fit and seal over the eye sockets. A pair of lenses in the eyepiece are positioned over the eyes to allow the user to substantially distortion free vision while protecting the eye from environmental irritants such as particulate matter, and air and water flow.
The lens that produces distortion free vision tends to be a planar lens that offers high resistance (high drag) to fluid flow past the lens. Conversely, a lens that is shaped for low drag tends to distort the image transmitted to the eye. There exist applications, such as swimming, where it is desirable for a lens to minimize visual distortion while at the same time minimizing drag.
The inventors are aware of patents that disclose devices which cooperate with a human face to reduce visual distortion due to light refraction across various media.
U.S. Pat. No. 3,040,616 (Simpson) discloses underwater goggles that are intended to address the problem of visual distortion underwater. The goggles are formed with recesses that allow water to flow between a flat window that is adjacent to the wearer's eyes and a curved rear lens. This patent relies on a pair of outer lenses separated from the inner lens by an air pocket to present an undistorted image to the wearer.
U.S. Pat. No. 2,317,658 (Welsh) discloses swimming goggles that have two spaced lenses. The space between the lenses, however, is not exposed to water.
U.S. Pat. No. 4,317,240 (Angerman et al.) discloses a pair of sports goggles that have a slot at the top portion of a lens for assisting air flow to pass between the lens to prevent fogging.
The lenses and seals of conventional swim goggles generally comprise a single relatively planar lens (to minimize visual distortion) mounted to a sealing member for engagement about the eye socket of a wearer. These swim goggles tend to rely on an interference fit between the seal and the face to produce an air pocket between the eye and the lenses. Of course, the generally flat lenses of conventional swim goggles are not streamlined resulting in increased hydro-dynamic drag. To reduce hydro-dynamic drag, it is necessary to increase the curvature of the lens, however, a curved lens tends to increase visual distortion and many users are not prepared to sacrifice clarity of vision for lower drag. The design considerations of minimal visual distortion and minimal drag are at odds with each other and to date users have had to sacrifice one in order to enjoy the other.